Various new next-generation memories have recently been proposed as alternatives to existing semiconductor memories, such as flash memories and DRAMs. Among them, magnetic random access memories (hereinafter, “MRAMs”), which can exhibit high-speed operation and can be micro-fabricated, are leading candidates as replacements for the DRAMs. MRAM memory elements are magnetoresistive effect elements. Each magnetoresistive effect element has, as a basic structure, a laminated structure comprising a reference layer of constant magnetization, a memory layer of variable magnetization, and a tunnel barrier layer interposed therebetween.